Driving and stopping mechanism.



J. KIEWICZ.

omvme AND STOPPING MECHANISM.

APPLICATION FILED SEPT. 4, 1913.

Patented June 27, 1916.

2 SHEETS-SHEET I.

Mgr-2X03; 5% @414 fakmfieeww J. MEWICZ.

omvmc AND STOPPING MECHANISM.

APPLICATION FILED SEPT. 4,19I3. ma n.

Patented. 511116 27, 1916.

2 SHEETSSHEET 2.

NTE ears a n r area.

JOHN -KIEWICZ, F HYDE PARK, MASSACHUSETTS, ASSIGNOR TO THE REECE BUTTON HOLE MACHINE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MAINE.

DRIVING AND STOPPING IHECH ANISM.

Specification of Letters Patent.

' Patented June at, rate.

. To all whom it may concern:

Be it known that I, JOHN KIEWICZ, a citizen of the United States, residing at Hyde Park, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Driving and Stopping Mechanism, of which the following is a specification, reference being had therein to the accompanying drawing.

This invention relates to driving and stopping mechanism and more particularly to a means for causing a stoppage of the stitching mechanism at the end of the stitch ing operation in a buttonhole sewing machine of the type referred to, for example, in my prior Patent 1,021,739, of March 26, 1919.. In such prior machine the stitching mechanism is sustained by a so-called movable stitch frame which has one movement to bring the stitching mechanism into or out of operative position, and another movement for feeding the stitching mechanism while operating upon the buttonhole. The first movement, which is a quick movement, is secured by means of a quick-feed shaft, while the slower feed movement of the frame is otherwise secured.

The general operation of this type of machine is that the quick-feed shaft is first connected to its driving mechanism, causing the frame to move quickly forward (after the cutting operation) into proper operative position relatively to the cut buttonhole, whereupon the quick-feed shaft is disconnected from its driving mechanism and the stitching mechanism automatically begins its operation, during which the frame has a slow feed movement as the stitching progresses. As soon as the buttonhole is completely stitched, the rapidly operating stitching mechanism must be automatically thrown out of operation at the proper point, and thereupon the quick-feed shaft is again connected to. its driving mechanism causing the frame to quickly return to initial position.

The present invention is shown as applied to effect the stoppage of the action of the stitching mechanism at the completion of the buttonhole. Such stoppage should occur before the quick-feed shaft is allowed to be driven for the return movement of the frame, to prevent accident. The stitching mechanism is driven from a high speed driving shaft which obviously must be to provide an improved driving mechanism,

having stopping means for effectively accomplishing these results, and, moreover, in

such way as to prevent excessive shock, noise and wear upon the fast rotating parts thus suddenly brought to stop.

Other objects will appear in after following description.

To the attainment of such objects the present invention consists in the novel mechthe hereinanisms, combinations, arrangements, details and other features shown and described 'in the accompanying drawings and specifications. First will be described one form in which the present invention may be embodied and thereafter the novel features will be pointed out in the claims. 7

In the accompanying drawing forming part hereof Figure 1 is-a right-side elevation of the rear end of a machine embodyin this invention,= showing the driving shaft for the stitching mechanism carried'by the movable stitch frame. Fig. 2 is a partial rear elevation of the parts shown in Fig. 1. Fig. 3 is a partial plan view showing some of the parts of'F-ig. 2. Fig. 4 is a partial left-hand elevation showing certain parts of Fig. 3. Fig. 5 is a rear elevation showipg certain parts of Fig. 3. Fig. 6 is a vertical section taken upon the plane 66 of Fig. 1. Fig. 7 is a cross-section of the brake device taken on the plane 77 of Fig.1. a

The same reference numerals are applied to the corresponding parts in the several figures of the drawings.

Upon the stationary frame 11 of the sewing machine is mounted the movable stitch frame 12 adapted to slide forwardly and backwardly, and carrying the stitching mechanism. The stitch frame is supported on the slidin base 13. The driving shaft 14 for the stitc ing mechanism is carried in the movable stitch frame. Upon the shaft '14 is a loose pulley 15 and a fast pulley 16 detachable portion 20 secured to the movable body portion 21 having at its lower end a forwardly and rearwardly extending pin or shaft 22 engaging in bearings 23 fast on the frame 11'. A collar 24 secured to the shaft between the bearings is provided with a lug 25 actuated by a spring 26 tending to keep the belt normally upon the fast pulley so that the stitching mechanism is driven unless rendered inoperative in the manner hereinafter described.

The stopping device 30, which is so constructed and connected as to effect both the shifting of the belt and the application of a brake, besides affording a positive stop, consists of a hollow upright portion 31 from which forwardly extends the arm portion 32 secured to a shaft or sleeve 33 so as to permit a swinging of the stop device 30 toward and from the driving shaft 14. I

Carried by the portion 31 is a yielding lug 34 adapted to engage a cooperating lug that rotates with the driving shaft. The lug 34 is formed at the upper end of a bolt 35 which is slidable upwardly and downwardly in the hollow interior of the portion 31. At the lower end the bolt 35 has a strong spring 36 applied between its head and the bottom of the portion 31, thereby tending to maintain the bolt and the lug 34 yieldingly in lowered position. As seen in Fig. 6, the portion 31 is so recessed at 37 as to form a stop determining the lowered position of the lug.

From a. hollow hub 40 secured on the driving shaft 14 projects a. lug or toe 41 which rotates with the shaft and at times is adapted to be engaged by the yielding lug 34. In Fig. 4 it is seen that the lug 41 is capable of a slight movement in a slot formed at 42 in the periphery of the hub. This slight movement of the lug is circumferential, the lug being provided with an annular portion or sleeve 43 surrounding the entire circular portion of the hub. A Strong spring 44 located behind the lug tends to break the shock when the two lugs meet, by permitting a slight yielding.

From the above it will be seen that swinging the stop device 30 toward the driving shaft places the lug 34 in the path of the fast rotating lug 41 causing the lugs to engage and tending to stop the shaft. At the same time it is herein proposed to not only shift the belt but to apply a brake and in such a way as to bring the parts accurately and easily to stopped position with the needles out of the work.

For automatically shifting the belt, the following simple expedient will suffice. Referring particularly to Fig. 2, the lower end of the portion 31 is provided with an inclined projection 48 adapted to engage a similar projection or incline 49 formed on the belt shifter portion 21. When the stopping device 30 is allowed to swing inward for causing the lugs to engage each other the inclined'projections 48 and 49 engage, the former rising and forcing the latter laterally to throw the belt shifter and shift the belt from the fast pulley 16 to the loose pulley 15.

A convenient automatic braking device may comprise the brake lever 53 yieldingly supporting a brake shoe 54, a spring 55 be ing interposed between the two in a manner indicated in Fig. 1 and in cross-section in Fig. 7. The brake lever is shown pivoted at 56 to a fixed bracket 57, and the rear extremity of the brake lever passes into recess 58 formed in the stop device portion 31, and into recess 59 in the bolt 35, as indicated in Figs. 1 and 6. lVl1en the stopping device swings to operative position, it lifts the brake lever and moves the brake shoe from the position shown into contact with the hub thus partially braking .the shaft. When the lugs meet and the bolt rises in the act of stopping the driving shaft, the bolt lifts the end of the brake lever and applies the brake shoe more forcibly to the periphery of the hub 40, thus supplementing the positive stop action of the lugs, and easing the action.

The connections for starting the quickfeed shaft for returning the stitch franc after the stitching is complete to the initial or cutting position are not fully shown, but are partially indicated as follows; a lever 66 shown partly in dotted lines in Fig. 1 controls the usual clutch for the quick-feed shaft. This lever 66, or rather the forward part of it 67, is engaged by the lower end of the downward arm 68 rearward rigidly connected with the arm portion 32 of the stopping device 30, so that when the latter is swung into operative position for stepping the stitching, the movement of the arm 68 permits the movement of lever 66 to start the quick-feed shaft and return the stitch frame .to initial position. Such movement of the lever 66 is usuallyefi'ected by a spring. A locking deviceis shown for preventing such movement of the lever 66 unless the stitching mechanism has been properly and exactly brought to rest. A locking lever or arm 71 is shown loosely mounted on the same shaft 33 already referred to, and extending downwardly therefrom into the horizontal path of an extension 74 formed on the lever 66. When the arm 71 is in the forward position shown, it prevents the lever 66 moving rearward for starting the quick-feed shaft. The lock lever comprises, not only the downward arm 71, but an upward arm 72 resting upon the periphery pulley 16 in such posit on that it may drop into notch 73 in said pulley when the parts are in the correct stopping position. At such times obviously the arm 71 is free to be swung backward, thereby permitting lever 66 to be moved for starting the quick-feed move ment, while at other times the quick-feed devices are locked against actuation.

For controlling the movement of the stopping device 30 between operative and inoperative positions, it may be provided wit an extension 77 forward of the shaft 33 with which it turns, and a contact pin 7 8 projecting from the extension which latter is moved upwardly or held upwardly or released to descend. by a control pin 79. This control pin may be vertically movable and operated from beneath the base 13, for example, by means of the operating cam or disk which also controls or'eifects the slow and .quick feed of the stitch frame during stitching. WVhen the stitching is completed, the pin 7 9 descending, permits the extension 77 to, descend, and permits the stopping device 30 to swing forwardly to bring lug 34 in the path of lug 41.

A spring may be employed for actually causing the forward swinging of the stopping device, thus in Fig. 2 the spring 82 pulls upwardly. on the rearwardly extending arm 83 carried on the same shaft 33 as the stopping device.

As an additional security or expedient for accurate stoppage. there is shown provided av spring guard 87 pivoted on the stopping device 30 to swing about a vertical axis, a spring 88 serving to press the free or forward end of the guard leftwise. The guard 87' is intended to cooperate with the hub 40 by reason of the notch 89 in said hub. Normally the spring guard is disengaged and inoperative as seen in Figs. 1 and 3, but when the stopping device 30 is swung forward, the guard is brought against the periphery of the hub, which prevents complete forward movement until the' shaft 14 has rotated to the point where the guard may drop into the notch 89, whereupon the stopping device moves fully forward into the position to bring the shaft 14 and the stitching mechanism to rest. The notch has a slanting exit so that the guard causes no interference with the rotation.

The arrangement is such that the notch 89 is so spaced on the hub 40 from the rotating projection 41, that the complete forward movement of the stopping device is permitted at a given time, namely, threequarters of a revolution in advance of the engagement of the projection 41 with the lug 34. This insures uniformity in the action of the stopping mechanism.

Generally the order of operation in bringing the shaft 14 to rest may be as follows: When at the end of the stitching the pin 79 permits the arm 77 to descend and the stopping device 30 to swing forward, the spring 82 comes into play, moving the stopping device partially inward This may occur at different points in the shafts rotation. The stopping device moves only partially inward, being restrained by the guard87 contacting the hub. Momentarily thefiparts stand in this position until the hub has rotated sutficiently to bring the notch 89 opposite the guard. At this time, which is three-quarters revolution before the final stoppage, the guard enters the notch, thus permitting the stopping device to complete its forward swinging. This forward swinging simultaneously throws the belt from the fast to the loose pulley, and applies the brake shoe to the periphery of the hub. During the next three-quarters revolution, the shaft being no longer driven, has a natural slowing down tendency. This, together with the drag of the brake, serves to largely overcome the momentum of the parts. Therefore, when finally the lug and projection meet, the speed has been largely reduced, and the blow occurs with but slight' force. Immediately upon the projection and lug meeting, they both yield as explained, thus additionally breaking the abruptness of the shock. Immediately the lug 34 commences to yield, it operates through the bolt 35 to forcibly lift the'brake lever and thereby more tightly apply the brake to the hub. As it were, the described parts cooperate by consecutive action to substantially bring the shaft to rest practically without shock, noise or injury. I

In explanation of the phraseology used in the claims the following further remarks will render the same more easily understood. The shaft 14 together with the fast pulley 16 and hub 40 all rotate together as one "member and the whole may be considered as the shaft with portions of conveniently enlarged diameterfor cooperation with the other elements. The stop device 30 is nonrotatable in the sense that it is not a part rotating with the shaft, but, on the contrary, it is shiftable to and from operative position. The stop device has ashaft engaging portion adapted to positively engage the shaft at the predetermined. stopping point in the shafts rotation, for example, when the needle and work are disengaged. By positively is meant in contradistinotion to frictionally. The action of the stop device is not that of a friction brake, but it positively bars further rotation. The shaft engaging portion or lug of the stop device is yielding so as to give to a limited extent when struck by the projection 41 rotating with the shaft. The belt shifter constitutes a shiftable disconnector serving for rendering inoperative the connections to the shaft from a source of power. The disconnector is shifted by connections actuated by the shifting movement of the stop device, so that the sha t i disconnected from power before the stop device has engaged the shaft forstopping. The brake lever and shoe constitute a braking means adapted for ,retarding the shafts rotation. The braking means is applied by connections actuated by the shifting movement of the stop device so that the shaft is retarded before the stop device engages the shaft. The recess 59 of the yielding portion 34-35 of the stop device, engaging the brake lever 53 constitutes a means whereby the yielding of the stop device serves to increase the braking action upon the shaft. The shifta'ble guard 87 is for preventing the stop device .moving into stop position and this guard is thrown off guard at a predetermined point in advance of the shafts stopping point by 'a means controlled by the shafts rotation, namely, the notched hub 40 rotating with the shaft. The guard 87 is to advantage carried by the stop device, though it might be otherwise mounted. The combination of the above recited elements is such that when the stopdevice is shifted into stopping position, it thereupon disconnects power and applies the brake and then, after a predetermined period, namely, three-quarters of a rotation, positively engages the shaft to stop it. In the full embodiment of the invention the positive engagement includes not only the engagement of lug 34 by projection 41, but also the increased braking action caused by and proportional to the yielding of the lug 34:.

It.will thus be seen that a sewing machine driving mechanism has been described at taining the objects and advantages before referred to, and other'advantages of the described mechanism will beapparent to those skilled in the art. Since many features of design, arrangement, detail and the like shaft engaging portion capable of limited yielding and adapted to engage the shaft at a predetermined stopping point in the shafts rotation, a shiftable disconnector for rendering inoperative the connections to said shaft from a source of power, a braking means adapted for retarding the shafts rotation,

means whereby the stop-device in its shifting movement effects the shifting of the disoonnector and the applying of the braking means, and means whereby the yielding of the stop-device under impact serves to increase the braking action upon the shaft; whereby when the stop-device is shifted into stopping position it thereupon disconnects power and applies the brake and then after a predetermined rotation positively'engages the shaft to stop it by impact and increased braking action.

2. A driving and stopping mechanism including in combination, a rotatable shaft from which operations are efl'ected, the same having a projection rotating with it, a non-rotatable shiftable stop-device having a yielding lug adapted tobe struck by said projection, a shiftable disconnector as a belt shifter for rendering inoperative the connections to said shaft from a source of power, a braking means adapted for retarding the shafts rotation, means whereby the stop-device in its shifting movement effects the shifting of the disconnector and the applying of the braking means, and means whereby the yielding of the stop-device lug serves toincrease the braking action upon the shaft; whereby when the stop-device is shifted into stopping position it thereupon disconnects power and applies brake and then after a predetermined rotation positively engages the shaft to stop it.

3-. A driving and stopping mechanism including in combination, a rotatable shaft from which operations are effected, a nonrotatable shiftable stop-device having a shaft engaging portion adapted to positively yieldingly engage the shaft at a predetermined stopping point in the shafts rotation, a shiftable disconnector as a belt shifter for rendering inoperative the connections to said shaft from a source of power, a braking means adapted for retarding the shafts rotation, means whereby the stop-device in its shifting movement effects the shifting of the disconnector and the applying of the braking means, means whereby the yielding of the stop-device serves to increase the braking action upon the shaft, a shiftable guard for preventing the stop-device moving into its stopping position, and means controlled by the shafts rotation for throwing the guard ofi guard at a predetermined point in advance of theshafts stopping point; whereby when the stop-device is shifted into stopping position it thereupon disconnects power and applies brake and then after a predetermined rotation positively engages the shaft to stop it.

4. A driving and stopping mechanism including in combination, a rotatable shaft from which operations are effected, the same having a pro ection rotating with it, a nonrotatable shiftable stop-device having a yielding lug adapted tobe struck by said projection, a shiftable disconnector as a belt shifter for rendering inoperative the connections to said shaft from a source of power, a braking means adapted for retarding the shafts rotation, means whereby the Stop-device in its shifting movement effects rotation positively engages the shaft to stop it. 7

5. A driving and stopping mechanism including in combination, a rotatable shaft from which operations are effected, a shiftable stop-device having a shaft engaging portion adapted to engage the shaft at a predetermined stopping point in the shafts rotation, a shiftable disconnector for rendering inoperative the connections to said shaft from a source of power, a braking means adapted for retarding the shafts rotation,

means whereby the stop-device in its shifting movement effects the shifting of the disconnector and the applying of the braking means, a shiftable guard for preventing the stop-device moving into its stopping position, and means controlled by the shafts rotation for throwing the guard off guard at a predetermined point in advance of the shafts stopping point.

6. A driving and stopping mechanism including in combination, a rotatable shaft from which operations are effected, the same having a projection rotating with it, a shiftable stop-device having a yielding lug adapted to be struck by said projection, a shiftable disconnector for rendering inoperative the connections to said shaft from a sourceof power, a braking means adapted for retarding the shafts rotation, means whereby the stop-device in its shifting movement eifects the shifting of the disconnector and the applying of the braking means, a shiftable guard carried by the stop-device for preventing the stop-device moving into its stolpping iposition, and means rotating with t e sha for throwing the guard off guard at a predetermined pointin advance of the shafts stopping point.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN KIEWICZ.

Witnesses:

THOMAS J. CARTY, WM. G. Borsvnn'r. 

